Automatic electric-circuit breaker



W. I. METER & L. RIDEOUT. AUTOMATIC ELECTRIC CIRCUIT BREAKBR.

APPLICATION FILED MAR.30,1908.

Patented Jan. 3, 1911.

2 SHEETS-SHEET l.

W. F. METER & W. L. RIDEOUT. AUTOMATIC ELEG TRIG CIRCUIT BREAKER.

APPLICATION FILILD MAR.3I0,1908.

Patented Jan.3,'1911.

2 SHEETS-SHEET 2v UNITED STATES PATENT OFFICE.

WILLIAM F. METER AND WILLIAM L. RIDEOUT, OF SHKOSH, WISCONSIN, ASSIGNORS TO ELECTRICAL MANUFACTURING COMPANY, F vOSHKOSI-I, WISCONSIN, A CORPO- RATION OF WISCONSIN.

AUTOMATIC ELECTRIC-CIRCUIT BREAKER speciecation of Letters Patent. Patent-ed Jan. 3, 1911.

Application led March 30, 1908. Serial No 424,215.`

United States, and residents of Oshkosh,

lVinnebago county, State of \7\7isco11sin, havef invented eertaln new and usetul Improvements Ain Automatic Electric-Circuit Breakers, of which the following is a specitication.

The presentinvention relates to automatic means for cutting ont an electric circuit when for any reason the voltage of the current passing through the circuitl increases beyond a safe limi Y It is well known that wires which are'designed for low potential. currents often become accidentally charged through contact.

with high potentialcircuits, and that in this way considerable loss ot life and loss of property through fire occurs.

The object of our invention is to produce an automatic cut-ont which will instantly break the. circuit when a current passes through it which is higher than the normal in potential.

Other objects of the invention are to produce an automatic cut-out which will becertain and positive in its operation and which -will not interfere with the normal operation of the svitch in opening and closing the circuit.

` The vinvention will be described' in conwhich,

Figure l is a face view of a switch embodying our invention; Fig'. 2 is a section on the line22 of F ig, 1 showing the switch closed; Fig. 3 'is a similar section showing the autonnitic devices in the act of I nection with the accompanying drawing, in

,Opening the switch; Figi-A is a sectional viewof .the'in'closed'air gap ,.Fig. 5 is a'section on the line, 5-5 of .F1g.`2; Fig. A(i 'is a section on thelneGe-Gfof Fig. l. "l

lReferring to the drawings, 1, l1, indicate the blades ot a knife switch which are pivotally connected. with the bindingv posts 2, 2, and which cooperates with suitable contacts 3, 3, fixed upon the base. A'As shownv the contacts 3, 3, are electrically connected with the binding posts 4, 4, by means of fuses 5,

C indicates the incoming and outgoing conductors of the circuitwhich'are connected with the binding posts 2 and 4.

The switch blades 1, 1, are connected at their free ends .with the cross bar 6 ot' insulating material and preferably provided with a handle 7.

It will be understood that the binding posts, switch blades, and other parts through which the current passes should be madelof coplper or other suitableV conducting materia le claiml no novelty for the switch thus tar described as the same is of a well known construction.

It will be understood that our :invention may be applied to many .different forms of switches and that the one herein described lis used merely for purposes of illustration.I

l t hashcretofore been proposed tolprovide a knife switch -with a detent which would be automatically releascd'if the `.circuit were overloaded and with a spring for throwing the" switch open when released. Such delvices have been found to be unreliable for the reason that the contacts corrode more or less and the` switch is likely to stick even when released from the detont. this ditiiculty we .provide what may be termed a hammer which is normally under tension lto move 'against the switch and is normally held away -from the switch by a suitable detent.- As shown in the drawing, the hammer H -is in the form of a lever which is pivoted at 8 to a post t), the pivot being preferably in line with they pivots 10 of the switch blades so that as the hammer follows the switch there will be no relative movement or friction between them. The hammer lever has an arm ll'to which is-conlnecteda spring 12 which constantly tends to throw the hammer outward into the position shown in Fig. 3. The hammer is normally held with its free'end near the basell ot the switch kby means oia d etentl4, as shown in Fig. 2; The detent is pivoted at 15 and to itsrear end is' connected a. rod 1G which eX- tends into the central opening in a solenoid S. T he rodv 16 preferably made ot' brass or other non-magnetic material Aso that. `it will not be affected bythe solenoid. .orstielc To obviate f tothe core or pllinger-of'thesolenloid. The

rod 1G is preferably provided with an eye. 17 throughl which' va hook -18 on the :detent passes. This t'orms a very convenient means ot connectingv the two parts in'such a vway that they cannot separate"accidentally, as shown in Figs. 2 and 5.

are in normal position, as shownin Fig. 2,;

and the hammer therefore acquires considerable momentum before striking the switch.

The inertia maybe regulated as required by increasing or decreasing the weight of the hammerlever and the strength' of the spring 12 which operates it and it will be understood that these' parts will be proportioned to the size ofthe switch to be operated. We

. have found that when properly constructed the hammer will invariably open 4t-he switch when it is released. `We also prefer to operate the detent 'to Arelease the hammer by means of a blow instead of'by pressureand for that reason we use the solenoid S and rovideit- Awith a c ore or plunger 19 .of soft lron which is normally supported on a rest.

20, its upper end being atsome distance from thedetent operatmg. rod 16. When the solenoid is energized the core is thrown up quickly and strikes the rod-16 a hammer blow, thus releasing the hammer H from the detent and permitting'it to y outward against the switch' and open the latter, as shownin Fig. 3. .y

Referring to'Fig. 1, -Eindicatts a line .to

I the ground froma binding post 21. vA second binding post 22 is connected with the post 21 by a conductor inclosed in'a casing 23 provided with a spark gap, which -will be hereinafter described in detail. The solenoid winding is connected with one of the binding posts 2 and with the post :22, and a high resis ince carbon rod 24vis also in cir-- cuit with one o f the binding posts 2 and the post"22, as .shown in Fig. 2.

spark gap in the casing 23 is arranged as follows, referring to Figa. lThe casingiis` constructed of -paper or other .non-conducting material and its ends are closed by metal caps 25. Centrally `arrangedy ini-the casing,

'is'a mi`ca disko'r partition 26"-h'aving an o'pening 27 which foi-ms an air gap between l 5 two carbon Ablocks 2S which are constantly pressed against the'micapartition by springs 29 bearing onv the' caps 25. It1 Awill be seen thatl any current having an electromotive force high enough to jump the gap 27 Awill pass from the cap 25 at one end of `the spark gapdevice to the, cap 25 at the` .otherpend Our 4invention contemplates inclosing the carbon blocks 28 and the mica disk 26 in an air tight manner so that combustion will not take place in the space 27, except to a very limited extent, .and the space will not therefore becone filled with ash.

' Referring to Figs. 1 and 6, 30 indicates a carbon 'plate supported on and electrically connected with each of the contacts 3- and 31 indicates a similar'plate supportedon and electrically connected with each of the switch blades 1. `These .carbon 'plates are preferably spring supported and the plates ,An inclosedl Ag3 esoi,

opened or closed. 4They are arranged so that in closing the switch the carbon plates will' engage before the switchblades'v reach the metal contacts and so that they will dismeta switch bladesand the metal -contacts and metal.

tofore described.

The operation of thel circuits i-sl as follows: A current of the normal potential for which the switchis designed will not pass the air 'gap-27 and'hence the solenoid will remain inactive. vShould 'thecircuit C- become charged with a current'of higher' potential than that for vwhich it isintended, the current will pass through` the solenoid and through thespark gap 27' to the ground,

core 19 to be thrown up a 'ainstf the rod 16 and the'hammer H vto be re eased, which will instantly openjthe circuit C. -The carbon block 2 4 is of higher resistance than the solenoid and is intendedto provide an additional path for lightnin or currents of extremely hi h voltage an frequency, to pre- ",vent the so enoidfromA beingburned out. It will be evident that the automatic operating device for the switch does not 1n any way interfere with the normal operation of the switch and that ,the same will remain either openv or closed, as 'may be desired, While the hammer lever islocked by the detent 14;

`claim and desire to secure by Letters'Patf ent is, 'Y f 1. ,In an electrical switch,thecombination adapted to strike Ithe mova le element and open the switch .';means for holding the hammer in set position .with its striking part behindthe movable element to permlt free operation of the switch when said hammer is in set position without disturbing the hammer. j

2. 'In an electricaliswitch, in combination, a base, a movable element mounted on a pivot on said base, a hammer insulated from ,the movable element mounted on a; pivot concentric with the pivot of the movableelevment, and means for latching the hammer in set position behind the movable element, said hammer being1 constructed to permit o ening andc'losing movement of the movable element without disturbing the hammer. l 3. In an electrical switch, in combination, l, a base, a movable element mounted on a pivot on said base, a hammer Ainsulated from l the movable element mounted on a pivot 31 rub on the plates 30 as the switch is thus prevent burning 'andcorrosion of the,

engage afterl the switch' blades leave the Y contacts when the switch is opened. In this way we prevent arcs between the- The operation of the switch has been herethus energizing the solenoid andcausing the ,Having described our invention what we .Spportmgg-Ael i. ment ofthe 'switchpf a ivoted hammer concentric with the pivot et the movable element, means for latcliing the hammer in .set position behind the movable clement, said hammer being constructed to permit Opening and cloeing movement of the movable element withoutdistuihing' the hainmei', and means controlled the voltage for releasingI the latching means.

4C. In an electifical'switch, the combination with a movable element 01": the Switch carrying switch contacts, ofv a hann'ner independent of the movable element and ewitch contacts located behind the switch and adapted to strike the movable element aud open the switch, and electromagnetic .means adapted to release the hannnei' Wliciehy the switch may be opened and closed independently of l `the operation of the liainnietz 5. In an electrical switch, the combination 20 with a movable element ot the switch carry ing,` switch contacts, of a spring-actuated pivoted hammer independent ot the Inovable element and switch contacts located 

